Introduction to the Method of Asphalt Viscosity

Definition of Viscosity

The force between the flow layers is called internal friction or viscous force. Liquid viscosity due to molecular gravity, when the liquid flows, the molecules of the fast layer try to pull the molecules of the slow layer forward, while the slow layer of the fast layer molecules as far as possible to pull back. These interactions between the molecules of the fluid allow the movement to be transmitted layer by layer, and maintain the velocity difference between the layers, presenting the viscosity of the fluid. According to the meaning of the expression of viscosity, measurement methods, can be divided into the following categories.

Classification of viscosity

1.Dynamic viscometer

The degree of viscosity is also known as dynamic viscosity. It is the properties that increase the resistance of the fluid against deformation, and the nature of the increase rate increases. The resistance generated by 1 square meter in the fluid is 1 square meter, 1m apart, and a relative movement speed of 1m/s.

2. Kinematic viscometer

Motor viscosity: The ratio of the dynamic viscosity of fluid to the density of the fluid at the same temperature is called motion viscosity. The use of gravity capillary viscosity meters can easily measure the viscosity of the movement.

In the ASTMD445 standard, motion viscosity is stipulated to calculate power viscosity, that is, power viscosity (PA.S) = density (kg/m3) × motion viscosity (m2/s).

3. Condition viscometer

Conditional viscosity is the ratio of the flow time measured by specific "viscosity meters" under specific conditions to the ratio of the flow time used by the standard solution. The viscosity of asphalt conditions used in road engineering includes Engeld viscosity, Saybolt viscosity, asphalt standard viscosity, etc.

4. Engler viscometer

The ratio of the time required for the time to flow out of the 200ml test solution from the viscosity meter to the time of distilled water at 20 ° C.

5. Saybolt viscometer

The time required for the 60ml test solution from Saybolt viscosity meter at the test temperature.

6. Standard viscometer

Under specific temperature conditions, the time required for 50ml asphalt out of the asphalt viscosity meter.

Detective method of viscosity

According to the physical significance of viscosity reactions and test methods, the test methods of liquid viscosity include capillary method, rotation method, falling body method, vibration method, skateboarding method, flowing cup method, etc. Depending on the temperature range and purpose of the measurement, the viscosity measurement methods commonly used in highway engineering are mainly the following. Use a vacuum decompression capacity to measure the asphalt's 60 °C power viscosity; use the inverse capsule viscosity meter and the BrookField viscosity meter for 135 °C and higher temperature; in order to evaluate the low temperature performance of the asphalt, the column and skateboard viscosity meter generally use The flowing performance of the asphalt under specific conditions, the viscosity meter adopted includes road asphalt standard viscosity meter, Engler viscosity meter, and Saybolt viscosity

1. Capillary method

GD-0620B-1 asphalt dynamic viscosity test device (vacuum decompression capacity)

GD-265E asphalt motion viscosity test device (capillary method)

2. Rotation method

GDJ-1C/1D/1F, Brookfield rotary viscometer

GD-0621-1 Bitumen standard viscosity tester

GD-1B-1 Engler viscosity meter

GD -0623 Saybolt heavy oil viscosity tester